2 This lecture will help you understand:Human population growthDifferent viewpoints on this growthPopulation, affluence, and technology’s effectsDemographyDemographic transitionFactors affecting population growthThe HIV/AIDS epidemicPopulation and sustainable development

4 Our world at seven billionPopulations continue to rise in most countriesParticularly in poverty-stricken developing nationsAlthough the rate of growth is slowing, we are still increasing in numbersIt would take 30 years, counting once each second, to count to a billion!It would take 210 years to count to 7 billion!

5 The human population is growing rapidlyOur population grows by over 80 million each yearIt took until 1800 to reach 1 billionIn 1930 (130 years later) we reached 2 billionWe added the most recent billion in 12 yearsDue to exponential growth, even if the growth rate remains steady, population will continue to grow

6 Rates of growth vary from region to regionAt today’s 1.2% global growth rate, the population will double in 58 years (70/1.2 = 58)If China’s rate had continued at 2.8%, it would have had 2 billion people in 2004

7 Is population growth a problem?Technology, sanitation, medication, and increased food increase populationDeath rates drop, but not birth ratesPopulation growth was seen as goodSupport for elderly, a larger labor poolThomas Malthus’ An Essay on the Principles of Population (1798)Humans will outstrip food suppliesWar, disease, starvation reduce populations

8 Paul Ehrlich’s Population Bomb (1968)Neo-Malthusians: population growth will increase faster than food productionPopulation growth causes famine and conflictCivilization would end by the end of the 20th centuryIntensified food production fed more people

10 Some governments fear falling populationsPolicymakers believe population growth increases economic, political, and military strengthBut growth is correlated with poverty, not wealthStrong, rich nations have low growth ratesWeak, poor nations have high growth ratesSome nations offer incentives for more childrenElderly need social services49% of non-European nations feel their birth rates are too high

12 Population growth with limited resourcesImpact equates to pollution or resource consumptionHumans use 25% of Earth’s net primary productionTechnology has increased efficiency and reduced our strain on resourcesResulting in further population growthFor example: increased agricultural productionModern China’s increasing affluence is causing:Increased resource consumptionFarmland erosion, depleted aquifers, urban pollutionChina shows us what the rest of the world can become

16 DemographyDemography: the application of population ecology to the study of change in human populationsAll population principles apply to humansEnvironmental factors limit population growthHumans raise the environment’s carrying capacity through technologyHow many humans can the world sustain?1–33 billion: prosperity to abject povertyPopulation growth can’t continue forever

19 Population distributionHumans are unevenly distributed around the globeUnpopulated areas tend to be environmentally sensitive (high S value in the IPAT equation)Vulnerable to humans (e.g., deserts, arid grasslands)

21 Age structures: Canada vs. MadagascarCanada’s age structure is balancedMadagascar’s age structure is heavily weighted toward the young

22 Changing age structures pose challengesChina’s age structure is changingIn 1970, the median age was 20By 2050, it will be 45By 2050, over 300 million will be over 65Fewer people will be working to support social programs

23 Many populations are agingMany populations are getting olderThey will need care and financial assistanceTaxes will increase for Social Security and MedicareBut fewer dependent children means lower crime ratesThe elderly can remain productive

25 Factors in population changeWhether a population grows, shrinks, or remains stable depends on rates of birth, death, and migrationBirth and immigration add individualsDeath and emigration remove individualsTechnological advances caused decreased deathsThe increased gap between birth and death rates resulted in population expansionNatural rate of population change = due to birth and death rates alone

27 Falling growth rates do not mean fewer peopleSlower rates of growth do not mean a decreasing population—population size continues to increase

28 Factors affecting total fertility rateTotal fertility rate (TFR) = the average number of children born to each femaleReplacement fertility = the TFR that keeps the size of a population stable (about 2.1)Causes of decreasing TFR:Medical care reduces infant mortalityUrbanization increases childcare costsChildren go to school instead of workingSocial Security supports the elderlyEducated women enter the labor force

29 Life expectancy is increasingIn countries with good sanitation, health care, and food, people live longerLife expectancy = average number of years that an individual is likely to continue to liveIncreases with reduced rates of infant mortalityUrbanization, industrialization, and personal wealth reduce infant mortality ratesDemographic transition = a model of economic and cultural changeExplains the declining death and birth rates in industrializing nations

30 The demographic transitionA stable pre-industrial state of high birth and death rates changes to a stable post-industrial state of low birth and death ratesAs mortality decreases, there is less need for large familiesParents invest in quality of lifeDeath rates fall before birth ratesResulting in population growth

32 The demographic transition’s four stagesPopulation growth is seen as a temporary phenomenon

33 Is the demographic transition universal?It has occurred in Europe, the U.S., Canada, Japan, and other nations over the past 200–300 yearsBut it may or may not apply to developing nationsThe transition could fail in cultures that:Place greater value on childbirth orGrant women fewer freedomsFor people to attain the material standard of living of North Americans, we would need the natural resources of four and a half more Earths

34 Birth control: key to controlling growthThe greatest single factor slowing population growthBirth control = controlling the number of children bornReducing the frequency of pregnancyContraception = deliberate prevention of pregnancy through a variety of methodsFamily planning = affects the number and spacing of childrenClinics offer advice, information, and contraceptivesHindered by religious and cultural influencesRates range from 10% (Africa) to 90% (China)

39 We are a long way from gender equityOver 60% of the world’s poor are womenViolence against women remains shockingly commonMany men resist women’s decision makingThe gap is obvious at high levels of governmentWe are a long way from achieving gender equalityThe U.S. lags behind the world in proportion of women representatives

40 Policies and family planning workMany countries provide incentives, education, contraception, and reproductive health careFunding and policies that encourage family planning lower population growth rates in all nationsThailand’s educational-based approach to family planning reduced its growth rate from 2.3% to 0.6%Brazil, Mexico, Iran, Cuba, and other developing countries have active programs1994’s UN population conference in Cairo, Egypt called for universal access to reproductive health care

41 Family planning reduces fertility ratesBlue = with family planningRed = without family planning

42 Poverty and population growth are correlatedPoorer societies have higher population growth ratesConsistent with the demographic transition theoryThey have higher fertility and growth rates, with lower contraceptive use99% of the next billion people added will be born in poor, less developed regions that are least able to support them

43 Correlation of poverty and populationPoverty exacerbates population growthPopulation growth exacerbates povertyIn 1960, 70% of all people lived in developing nationsAs of 2010, 82% live in these nations99% of the next billion will be born in these nations

45 Wealth also impacts the environmentThe population problem is not only in poor countriesAffluent societies have enormous resource consumption and waste productionPeople use resources from other areas, as well as from their ownEcological footprints are hugeWe are living beyond our meansOne American has as much environmental impact as 4.5 Chinese or 10 Indians or 19 Afghans

47 The wealth gap and population growth cause conflictThe contrast between rich and poor societies causes social and environmental stressThe richest 20% use 86% of the world’s resourcesIncreasing tensions between “haves” and “have-nots”

48 HIV/AIDS impacts African populationsThe AIDS epidemic is having the greatest impact since the Black Death in the 14th centuryOf 33 million infected, two-thirds live in sub-Saharan Africa; 3,800 die/dayLow rates of contraceptive use spread the diseaseHIV is established and spreading quickly around the world

49 AIDS has severe effectsAIDS undermines the ability of poor nations to developMillions of orphans are createdFewer teachers and workers to fill jobsFamilies and communities break downIncome and food production declineDebt and medical costs skyrocket

51 Sustainable development and populationMillennium Development Goals = UN’s declarationSpecific targets can be met with concrete strategiesGlobal partnerships with corporations, governments, etc.Population control is not a goalBut to achieve the goals, population growth and resource consumption must be addressed

53 Conclusion The human population is larger than at any other timeRates are decreasing but populations are still risingMost developed nations have passed through the demographic transitionExpanding women’s rights slows population growthHow will the population stop rising?The demographic transition, governmental intervention, or disease and social conflict?Sustainability requires a stabilized population to avoid destroying natural systems

54 QUESTION: ReviewWhat has accounted for most of the world’s population growth in recent years?a) Women are having more babies.b) Technology, medicine, and food have decreased death rates.c) Fewer women are using contraceptives.d) Nothing, the population has dropped in recent years.Answer: b

55 QUESTION: ReviewAccording to the I = P x A x T x S formula, what would happen to the impact if China’s 1 billion people had a lifestyle like Americans?a) Their population would automatically drop.b) Their population would automatically increase.c) Their affluence and technology would increase.d) Their impact on the environment would decrease.Answer: c

56 QUESTION: Review Where is the highest density of people found?a) In the colder climates (e.g., Siberia)b) In temperate or tropical biomesc) In rural areasd) In drier areasAnswer: b

57 QUESTION: ReviewAn age structure diagram shaped like a pyramid, with a wide base shows an ________ population.a) Increasingb) Decreasingc) Stabled) OlderAnswer: a

58 QUESTION: ReviewDescribe the relationship between population growth rates and population size.a) Falling growth rates automatically mean a smaller population.b) Falling growth rates automatically mean a larger population.c) Falling growth rates means we no longer have a population problem.d) Falling growth rates does not mean a smaller population, but that rates of increase are slowing.Answer: d

59 QUESTION: Weighing the IssuesShould the United States fund international family- planning efforts?a) Yes, absolutelyb) Yes, but only in nations that follow U.S.-approved programsc) Only if it can influence the nations’ policiesd) Never under any circumstances, it’s not our jobAnswer: any

60 QUESTION: Weighing the IssuesWould you rather live in a country with a larger population or smaller population?a) Small population, so there will be more resources for meb) Small population, so there will be more resources for others, including wildlifec) Large population, so I can find a dated) Large population, because people are our biggest resourceAnswer: any

61 QUESTION: Interpreting Graphs and DataWhat happens during the “transitional” stage of the demographic transition?High birth and death rates rise - population increasesHigh birth and death rates - population is stableHigh birth rates with low death rates - population increasesLow birth and death rates cause - population decreasesAnswer: c

62 QUESTION: Interpreting Graphs and DataAccording to this age pyramid, Madagascar’s future population will be:a) Balancedb) Largerc) Much largerSmallerMuch smallerAnswer: c

63 QUESTION: Interpreting Graphs and DataAccording to these graphs, which countries had access to family planning?a) Iraq and Pakistanb) Malawi and Haitic) Malawi and KenyaKenya and BangladeshAnswer: c